150 HYLOBATES 
bough, and tree to tree, in many a graceful swing and curve, rivaliing in 
its swift flight that of the feathered inhabitants of its leafy abode. 
The great peculiarity of the Gibbon is its exceedingly long fore- 
arm, which so lengthens the entire arm that the tips of the fingers can 
touch the ground if the animal should stand erect, for the slender hand 
is longer than the foot, and the thumb is long in proportion. 
The voice is wonderfully powerful, and can be heard for a great 
distance. Gibbons go in troops, and call early in. the morning when 
they may be heard howling in chorus, and at such times the volume of 
sound is phenomenal. But one young is produced at a time and this 
is carried by the mother under her body, the little one clinging to her 
fur with hands and feet, its weight seeming not to have the slightest 
effect on the female as she makes her way through the forest by 
prodigious swings. 
The Gibbon is a very delicate animal, in spite of its selecting 
usually an elevated habitat, and rarely survives long in captivity, 
generally succumbing to. some pulmonary complaint. As a rule it 
is very gentle, sometimes even affectionate, and does not object to 
being handled even by strangers, coming close up to the side of its 
cage and inserting its hand and at times its entire arm between the bars, 
and regarding with grave attention any one who may take its hand and 
gently stroke the arm. 
Most of the recognized species are very variable in coloring and 
this appears to be regulated by no rule, but is merely an individual 
peculiarity. The Gibbons never leave the forests of the more elevated 
tracts of their habitats, and one species only goes to the vicinity of 
the coasts, the SyMPHALANGUS SYNDACTYLUS of Sumatra. 
LITERATURE OF THE SPECIES. 
1771. Linneus, Mantissa Plantarum. 
HyYyLoBaTES LAR first described as Homo lar. 
1775. Schreber, Die Saéugthiere. 
HYLoBATES LAR redescribed as Simia longimana. 
1809. Latreille, in Sonini Edition Histoire Naturelle de Buffon. 
HYLOBATES LAR redescribed as Pithecus varius. 
1812. E. Geoffroy, in Annales du Muséum ad Histoire Naturelle, Parts. 
HyYLoBaATES AGILIS Cuv., (1821), called Pithecus lar nec 
(Linn.) ; and Hyzosates Lar redescribed as Pithecus varie- 
gatus; and H. Leuciscus first described as Pithecus leuciscus. 
1820. Kuhl, Beitrage zur Zoologie und vergleichenden Anatomie. 
